It is well known in the art to supply a roll of pre-opened bags for sealing a product in a bag with a bag filling machine, such as disclosed in U.S. Pat. No. 6,742,317.
However, a roll of pre-opened bags has a diameter, which is about twice the size of a roll of sealed film without pre-openings in the bags. Air trapped in the pre-opened bags makes the roll twice the size of a roll of sealed film. The cost of a roll of pre-opened bags compared to a roll of unopened bags is about twice the cost.
The pre-opened bags are created by forming end perforations in the two layers of the film and separating the end perforations in one of the layers in a secondary operation to open the bags and rewinding the open bags on to a core to form a roll with the bags oriented in the proper direction for feeding into a bag filling machine. This additional step of rewinding the open bags requires additional time in the manufacturing process and as such is an added cost.
Moreover, the pre-opened bags are all a standard size per roll, which to change the size of the bag requires changing the roll feeding into the machine. There is a need to be able to change the size of the bag on demand without changing the roll.
Accordingly, there is a clearly felt need in the art for a method and apparatus for making open bags in a manner that reduces the cost of the rolls of material and increases productivity of a bag sealing operation without changing roll to change bag size and without changing the roll as often because more bags are present per same diameter roll.